I've written previously about the productivity benefits of having dual monitors attached to your computer. But here's a new idea...the Mimo 710. This is a tiny $129 USD, 7-inch, 800 x 480 pixel monitor that plugs into your USB port.
I can think of several uses for this:
1. For use as a second monitor on computer systems that don't have a dual video card to support two full-size monitors
2. For use as a second monitor in areas where there isn't enough desk space for two full-size monitors
3. For use as a third monitor, for those who already have two large monitors. Could be an ideal dedicated space for iTunes, IM, Twitter, or email.
4. For use as a second monitor for travel for laptop users.